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中亚荒漠区沙拐枣属的分布格局与物种多样性 被引量:1
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作者 冯缨 宋凤 +2 位作者 金光照 Komiljon Tojibaev 葛学军 《生物多样性》 北大核心 2025年第8期66-75,共10页
本研究旨在系统解析沙拐枣属(Calligonum)的物种多样性、分布格局及环境适应机制,为其分类修订提供科学依据。研究方法包括:整合全球分类学数据及全球生物多样性信息网络(GBIF)等多源数据库,以厘清其全球分布格局;基于Tashkent Plant He... 本研究旨在系统解析沙拐枣属(Calligonum)的物种多样性、分布格局及环境适应机制,为其分类修订提供科学依据。研究方法包括:整合全球分类学数据及全球生物多样性信息网络(GBIF)等多源数据库,以厘清其全球分布格局;基于Tashkent Plant Herbarium(TASH)馆藏标本开展中亚地区瘦果形态测量与比较;结合多学科文献,探讨其系统发育关系、染色体变异及生态适应机制。结果表明:沙拐枣属广泛分布于自撒哈拉至中亚的干旱区域,其中中亚为分布与多样性中心(共记载34种),中国作为分布东缘共发现23种,与中亚共有种有17种,呈现典型的环古地中海间断分布格局,这可能与喜马拉雅隆升等地质事件相关。该属分布受水分、温度和土壤因子的共同影响,主要集中于年降水量低于200 mm的干旱区,物种间水分利用策略差异显著,低温与季节性温度变化限制其向北扩散,土壤偏好低盐、强碱性及沙壤类型。通过生理调节与化学计量等多层次策略适应干旱环境,并表现出明显的生态位分化。依据传统形态分类可将其划分为4个组,但分子系统学研究表明其组间存在交叉与嵌入,传统分类体系亟待修订。果实形态变异显著,基翅组可能为杂交起源,表现为果实偏大。细胞遗传学分析显示染色体以二倍体和四倍体为主,二倍体多分布于环境稳定区域,而多倍体更常见于生境异质性较高的地区。系统发育分析支持该属为单系群,但种间关系复杂,存在高遗传分化、有限基因流及非单系起源等现象,干旱加剧可能进一步促进了种系分化。沙拐枣属作为中亚干旱区关键类群,具有丰富的物种多样性及快速演化潜力。今后需整合基因组学与生态学等多学科方法,深化对其物种形成与适应机制的认识,并推进以种质保存与生态修复为核心的综合保护策略,以实现该属及其生态功能的长期可持续存续。 展开更多
关键词 中亚荒漠区 沙拐枣属 分布中心 物种多样性
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射流强化气液两相流体动力学特性的数值模拟
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作者 董鑫 薛璨 +2 位作者 单永瑞 冯颖 张建伟 《过程工程学报》 北大核心 2025年第8期820-833,共14页
在气液两相流中气泡射流的流体动力学特性影响气液两相间的传质传热及动量交换,对于强化气液两相间的混合至关重要。为探究幂律流体中气泡射流流动特性,采用数值模拟方法对气泡射流的动力学及水力学特性进行研究。考察了清水和不同浓度... 在气液两相流中气泡射流的流体动力学特性影响气液两相间的传质传热及动量交换,对于强化气液两相间的混合至关重要。为探究幂律流体中气泡射流流动特性,采用数值模拟方法对气泡射流的动力学及水力学特性进行研究。考察了清水和不同浓度羧甲基纤维素钠(CMC)水溶液中,气液比和液相流变特性对气相速度、气泡尺寸、气含率分布及气液两相流态的影响。研究表明,由于气相的扩散运动以及对液相环境的扰动,流场内存在涡旋结构,增强了气液两相间相互作用。随气液比增大,流场内湍动剧烈,促进气液两相混合,扩散了流线,流线分布疏散。气泡直径增大,气泡尺寸分布由单峰逐渐向双峰转变,且随液相浓度增加气泡直径分布范围增大。相较于清水,CMC水溶液中气泡射流气含率低,气泡分散宽度增加,气泡射流的流动行为发生变化。随气液比增加,流场内湍动加强,气泡射流核心处气相体积分数增加,涡结构强化了局部混合。气相向液相环境中的分散宽度增加,气液界面的有效接触面积增加,气液两相间的传质效率提高,且随液相浓度增加分散效果更明显。 展开更多
关键词 气泡射流 幂律流体 数值模拟 气液两相流
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基于质谱的RNA及其修饰分析 被引量:1
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作者 冯莹 何晓丽 +1 位作者 刘宇 王进 《遗传》 北大核心 2025年第8期885-902,共18页
核糖核酸(RNA)是一类关键的生物分子,负责遗传信息的传递、蛋白质的合成及其调控,以及众多生化过程的调节。它们也是许多病毒的关键组成部分。经过化学修饰的合成RNA或寡核糖核苷酸正越来越被广泛地用作治疗药物和疫苗。对于检测、测序... 核糖核酸(RNA)是一类关键的生物分子,负责遗传信息的传递、蛋白质的合成及其调控,以及众多生化过程的调节。它们也是许多病毒的关键组成部分。经过化学修饰的合成RNA或寡核糖核苷酸正越来越被广泛地用作治疗药物和疫苗。对于检测、测序、识别和量化RNA及其修饰的技术需求,远远超过了对DNA相关技术的需求。目前,质谱分析法已成为用于识别、测序和量化RNA及其修饰的主要技术方法。本文主要综述了质谱分析法在RNA及其修饰研究中的最新进展,并探讨了该技术方法的优劣势,旨在为读者提供从技术基础到应用前景的全面视角,推动质谱在RNA研究中的更广泛应用,并为领域内方法开发者和生物学研究者提供重要参考。 展开更多
关键词 RNA修饰 转录后修饰 表观转录组 质谱 LC-MS/MS
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Machine learning model using immune indicators to predict outcomes in early liver cancer 被引量:1
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作者 Yi Zhang Ke Shi +1 位作者 ying feng Xian-Bo Wang 《World Journal of Gastroenterology》 2025年第5期43-56,共14页
BACKGROUND Patients with early-stage hepatocellular carcinoma(HCC)generally have good survival rates following surgical resection.However,a subset of these patients experience recurrence within five years post-surgery... BACKGROUND Patients with early-stage hepatocellular carcinoma(HCC)generally have good survival rates following surgical resection.However,a subset of these patients experience recurrence within five years post-surgery.AIM To develop predictive models utilizing machine learning(ML)methods to detect early-stage patients at a high risk of mortality.METHODS Eight hundred and eight patients with HCC at Beijing Ditan Hospital were randomly allocated to training and validation cohorts in a 2:1 ratio.Prognostic models were generated using random survival forests and artificial neural networks(ANNs).These ML models were compared with other classic HCC scoring systems.A decision-tree model was established to validate the contri-bution of immune-inflammatory indicators to the long-term outlook of patients with early-stage HCC.RESULTS Immune-inflammatory markers,albumin-bilirubin scores,alpha-fetoprotein,tumor size,and International Normalized Ratio were closely associated with the 5-year survival rates.Among various predictive models,the ANN model gene-rated using these indicators through ML algorithms exhibited superior perfor-mance,with a 5-year area under the curve(AUC)of 0.85(95%CI:0.82-0.88).In the validation cohort,the 5-year AUC was 0.82(95%CI:0.74-0.85).According to the ANN model,patients were classified into high-risk and low-risk groups,with an overall survival hazard ratio of 7.98(95%CI:5.85-10.93,P<0.0001)between the two cohorts.INTRODUCTION Hepatocellular carcinoma(HCC)is one of the six most prevalent cancers[1]and the third leading cause of cancer-related mortality[2].China has some of the highest incidence and mortality rates for liver cancer,accounting for half of global cases[3,4].The Barcelona Clinic Liver Cancer(BCLC)Staging System is the most widely used framework for diagnosing and treating HCC[5].The optimal candidates for surgical treatment are those with early-stage HCC,classified as BCLC stage 0 or A.Patients with early-stage liver cancer typically have a better prognosis after surgical resection,achieving a 5-year survival rate of 60%-70%[6].However,the high postoperative recurrence rates of HCC remain a major obstacle to long-term efficacy.To improve the prognosis of patients with early-stage HCC,it is necessary to develop models that can identify those with poor prognoses,enabling stratified and personalized treatment and follow-up strategies.Chronic inflammation is linked to the development and advancement of tumors[7].Recently,peripheral blood immune indicators,such as neutrophil-to-lymphocyte ratio(NLR),platelet-to-lymphocyte ratio(PLR),and lymphocyte-to-monocyte ratio(LMR),have garnered extensive attention and have been used to predict survival in various tumors and inflammation-related diseases[8-10].However,the relationship between these combinations of immune markers and the outcomes in patients with early-stage HCC require further investigation.Machine learning(ML)algorithms are capable of handling large and complex datasets,generating more accurate and personalized predictions through unique training algorithms that better manage nonlinear statistical relationships than traditional analytical methods.Commonly used ML models include artificial neural networks(ANNs)and random survival forests(RSFs),which have shown satisfactory accuracy in prognostic predictions across various cancers and other diseases[11-13].ANNs have performed well in identifying the progression from liver cirrhosis to HCC and predicting overall survival(OS)in patients with HCC[14,15].However,no studies have confirmed the ability of ML models to predict post-surgical survival in patients with early-stage HCC.Through ML,a better understanding of the risk factors for early-stage HCC prognosis can be achieved.This aids in surgical decision-making,identifying patients at a high risk of mortality,and selecting subsequent treatment strategies.In this study,we aimed to establish a 5-year prognostic model for patients with early-stage HCC after surgical resection,based on ML and systemic immune-inflammatory indicators.This model seeks to improve the early monitoring of high-risk patients and provide personalized treatment plans. 展开更多
关键词 Hepatocellular carcinoma Inflammation Machine learning Prognosis Artificial neural networks Immune biomarkers
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Differential response of root morphology to potassium deficient stress among rice genotypes varying in potassium efficiency 被引量:38
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作者 Yan-bo JIA Xiao-e YANG +1 位作者 ying feng Ghulam JILANI 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2008年第5期427-434,共8页
Disparity in the root morphology of six rice(Oryza sativa L.) genotypes varying in potassium(K) efficiency was studied with three K levels:5 mg/L(low),10 mg/L(moderate) and 40 mg/L(adequate) in hydroponic culture. Mor... Disparity in the root morphology of six rice(Oryza sativa L.) genotypes varying in potassium(K) efficiency was studied with three K levels:5 mg/L(low),10 mg/L(moderate) and 40 mg/L(adequate) in hydroponic culture. Morphological parameters included root length,surface area,volume and count of lateral roots,as well as fine(diameter<0.2 mm) and thick(diameter>0.2 mm) roots. The results indicate that the root growth of all genotypes was reduced under low K,but moderate K deficiency increased the root length of the efficient genotypes. At deficient and moderate K levels,all the efficient rice genotypes developed more fine roots(diameter<0.2 mm) than the inefficient ones. Both fine root count and root surface area were found to be the best parameters to portray K stress in rice. In accordance with the root morphology,higher K concentrations were noted in shoots of the efficient genotypes when grown at moderate and deficient K levels,indicating that root morphology parameters are involved in root uptake for K and in the translocation of K up to shoots. K deficiency affected not only the root morphology,but also the root ultra-structure. The roots of high-efficient genotypes had stronger tolerance to K deficient stress for root membrane damage,and could maintain the developed root architecture to adapt to the low K growth medium. 展开更多
关键词 Genotypic difference Potassium (K) efficiency Root surface area Fine root development Root cell utra-structure
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Assessment of liver stiffness measurement-related markers in predicting liver-related events in viral cirrhosis with clinically significant portal hypertension
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作者 Yan-Qiu Li Yong-Qi Li +4 位作者 Jin-Ze Li Bing-Bing Zhu Yu Lu ying feng Xian-Bo Wang 《World Journal of Hepatology》 2025年第8期257-271,共15页
BACKGROUND Clinically significant portal hypertension(CSPH)is a crucial prognostic deter-minant for liver-related events(LREs)in patients with compensated viral cir-rhosis.Liver stiffness measurement(LSM)-related mark... BACKGROUND Clinically significant portal hypertension(CSPH)is a crucial prognostic deter-minant for liver-related events(LREs)in patients with compensated viral cir-rhosis.Liver stiffness measurement(LSM)-related markers may help to predict the risk of LREs.AIM To evaluate the value of LSM and its composite biomarkers[LSM-platelet ratio(LPR),LSM-albumin ratio(LAR)]in predicting LREs.METHODS This study retrospectively enrolled compensated viral cirrhosis patients with CSPH.The Cox regression model was employed to examine the prediction of LSM,LPR,and LAR for LREs.The model performance was assessed through receiver operating characteristic,decision curve,and time-dependent area under the curve analysis.The Kaplan-Meier curve was used to evaluate the cumulative incidence of LREs,and further stratified analysis of different LREs was per-formed.RESULTS A total of 598 patients were included,and 319 patients(53.3%)developed LREs during follow-up.Multivariate proportional hazards modeling demonstrated that LSM,LPR,and LAR were independent predictors of LREs.LPR had better performance in predicting LREs than LAR and LSM(area under the curve=0.780,0.727,0.683,respectively,all P<0.05).The cumulative incidence of LREs in the high-risk group were significantly higher than that in the low-risk group(P<0.001).Among the different LREs,LPR was superior to LSM and LAR in predicting liver decompensation,while the difference in predicting hepatocellular carcinoma and liver-related death was relatively small.CONCLUSION LPR is superior to LSM and LAR in predicting LREs in compensated viral cirrhosis patients with CSPH,especially in predicting liver decompensation. 展开更多
关键词 Liver stiffness measurement Liver stiffness measurement-platelet ratio Liver stiffness measurement-albumin ratio Liver-related events Clinically significant portal hypertension Viral cirrhosis
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Composition Analysis of Lycophytes and Ferns in Yunzhongshan Nature Reserve, Fujian Province
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作者 Jinquan SHEN Minyong LU +4 位作者 Baohua WU Lingming LIN Jinhuo HE ying feng Yinbing XIE 《Plant Diseases and Pests》 2025年第2期34-37,共4页
[Objectives]To analyze the composition of lycophytes and ferns in Yunzhongshan Nature Reserve,Fujian Province.[Methods]This study examined the composition of lycophytes and ferns in Yunzhongshan Nature Reserve through... [Objectives]To analyze the composition of lycophytes and ferns in Yunzhongshan Nature Reserve,Fujian Province.[Methods]This study examined the composition of lycophytes and ferns in Yunzhongshan Nature Reserve through field investigations and specimen identification,supplemented by a review of relevant literature.[Results]A total of 84 species of lycophytes and ferns were identified,encompassing 55 genera and 29 families.This included 14 species of lycophytes distributed across 8 genera and 3 families,as well as 70 species of ferns belonging to 47 genera and 26 families.Polypodiaceae and Selaginella were the dominant family and genus,respectively,while oligospecific families and monotypic genera were significant components of lycophytes and ferns in the region.The distribution types of these families were primarily cosmopolitan and tropical.The Germline differentiation degree(SD)was 3.34,and the proportion of rare or endangered species among lycophytes and ferns was 8.33%.[Conclusions]Yunzhongshan Nature Reserve possesses a diverse array of lycophyte and fern species.This study offers valuable scientific insights that can inform efforts related to the conservation of biodiversity,resource utilization and development,species introduction,and system evolution of lycophytes and ferns within the reserve. 展开更多
关键词 NATURE RESERVE LYCOPHYTES FERNS COMPOSITION
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Modulation of gut microbiota and serum metabolome by Apostichopus japonicus derived oligopeptide in high-fructose diet-induced hyperuricemia in mice
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作者 Jun Zhou Ziyan Wang +9 位作者 Zhixuan Zhang Jiaojiao Han ying feng Jing Zhang Zhen Zhang Ye Li Tinghong Ming Chenyang Lu Rixin Wang Xiurong Su 《Food Science and Human Wellness》 2025年第1期161-174,共14页
Fructose consumption has risen dramatically in recent decades due to the use of sucrose and high fructose corn syrup in beverages and processed foods,contributing to rising rates of hyperuricemia.The purpose of this e... Fructose consumption has risen dramatically in recent decades due to the use of sucrose and high fructose corn syrup in beverages and processed foods,contributing to rising rates of hyperuricemia.The purpose of this experiment was to explore the anti-hyperuricemia effects of an active oligopeptide(GPSGRP)derived from sea cucumber in fructose induced hyperuricemia mouse model,and to clarify the underlying mechanism in sight of gut microbiota and serum metabolites.Peptide GPSGRP treatment rebalanced uric acid metabolism and alleviated inflammatory response in mice.In addition,treatment with GPSGRP decreased the abundance of Bacteroides and Proteobacteria at the phylum level,Muribaculum,Prevotella and Bacteroides at the genus level,and inhibited the related pathways of purine metabolism and glycolysis/gluconeogenesis metabolism.Moreover,serum metabolites,including linoleic acid,indole and its derivatives,arachidonic acid and uridine,as well as related metabolic pathways,such as tricarboxylic acid cycle,ketone production and sugar production,were altered in response to GPSGRP treatment.This study provides a valuable reference for the application and development of marine biological peptides in uric acid management. 展开更多
关键词 FRUCTOSE HYPERURICAEMIA OLIGOPEPTIDE Gut microbiota Serum metabolomics
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Positive effects of applying endophytic bacteria in eggplant-Sedum intercropping system on Cd phytoremediation and vegetable production in cadmium polluted greenhouse 被引量:4
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作者 Luyao Ma Lukuan Huang +5 位作者 Qizhen Liu Shunan Xu Zheyu Wen Shuai Qin Tingqiang Li ying feng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2022年第5期383-391,共9页
The combination of intercropping and phytoremediation in the remediation of cadmium contaminated soil is an emerging model in recent years,but the results of previous studies are inconsistent.In the field experiment,e... The combination of intercropping and phytoremediation in the remediation of cadmium contaminated soil is an emerging model in recent years,but the results of previous studies are inconsistent.In the field experiment,eggplant was intercropped with hyperaccumula-tor Sedum alfredii Hance(inoculated or not inoculated with endophytic bacteria)to study the effects of intercropping on vegetable safety production,phytoremediation efficiency of hyperaccumulator and variation of soil available nutrients.The results showed that the in-tercropping treatment had a negative effect on the growth of eggplant and Sedum,but en-dophyte SaMR12 alleviated the inhibition of intercropping on plant growth.Intercropping treatment increases the Cd concentration in edible part of eggplant to 1.34 mg/kg compared with eggplant monoculture(1.19 mg/kg).While the application of SaMR12 reduces the Cd concentration of eggplant fruit to 0.95 mg/kg and significantly promotes the Cd uptake by Sedum.What's more surprising is that compared with eggplant monocropping,the con-tent of soil available nitrogen,phosphorus and potassium in the treatment of intercropping with inoculated Sedum increased significantly.And according to the correlation analysis of various indexes of plants and soil,the Cd content of eggplant is negatively correlated with the available phosphorus and potassium in the soil,while the Cd content of Sedum is positively correlated with it,which suggested that the application of phosphorus and potas-sium fertilizers in this experimental site was beneficial to reduce Cd content in eggplant and improve Cd phytoextraction of Sedum.Therefore,in the daily production of moderately Cd-contaminated soil,intercropping eggplant with Sedum inoculated with endophytic bacteria is an excellent Phytoextraction Coupled with Agro-safe-production(PCA)pattern. 展开更多
关键词 Endophytic bacteria Solanum melongena L. Cd pollution PHYTOREMEDIATION Soil fertility
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质量信息不对称下考虑参考价格效应的灰市供应链定价决策 被引量:2
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作者 冯颖 魏敏 +1 位作者 何文豪 张炎治 《中国管理科学》 CSSCI CSCD 北大核心 2024年第6期207-218,共12页
以一个制造商和一个分销商构成的灰市供应链为研究对象,考虑分销商参与灰市投机且灰市消费者购买意愿受参考价格效应影响的情形,探究了产品质量信息不对称对制造商披露策略选择及灰市供应链定价决策的影响。首先,以产品质量信息对称为... 以一个制造商和一个分销商构成的灰市供应链为研究对象,考虑分销商参与灰市投机且灰市消费者购买意愿受参考价格效应影响的情形,探究了产品质量信息不对称对制造商披露策略选择及灰市供应链定价决策的影响。首先,以产品质量信息对称为基准情形,构造了制造商主导的Stackelberg博弈模型,发现存在一个消费者对低价产品估值上限的阈值,使得低于(不低于)该阈值时,灰市存在(不存在)且系统取得内点(边界)均衡。质量信息不对称情形下,无论灰市存在与否,均存在唯一的质量披露阈值,使得制造商披露和隐瞒质量时的利润相等,该阈值大小受低价产品估值上限和参考价格效应强度等因素的影响;灰市存在时,制造商无论选择披露还是隐瞒策略,低价产品估值上限和参考价格效应强度的增加将抑制分销商的灰市投机行为;信息不对称并非一定有利于制造商,当且仅当制造商隐瞒质量信息时,信息不对称可能会使制造商受益;制造商披露质量时,分销商参与灰市投机会对制造商产生不利影响,而隐瞒质量时,分销商是否参与灰市投机对制造商无影响。 展开更多
关键词 灰色市场 参考价格效应 信息不对称 质量披露
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Ethylene accelerates maize leaf senescence in response to nitrogen deficiency by regulating chlorophyll metabolism and autophagy 被引量:4
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作者 Jiapeng Xing ying feng +3 位作者 Yushi Zhang Yubin Wang Zhaohu Li Mingcai Zhang 《The Crop Journal》 SCIE CSCD 2024年第5期1391-1403,共13页
Leaf senescence is an orderly and highly coordinated process,and finely regulated by ethylene and nitrogen(N),ultimately affecting grain yield and nitrogen-use efficiency(NUE).However,the underlying regulatory mechani... Leaf senescence is an orderly and highly coordinated process,and finely regulated by ethylene and nitrogen(N),ultimately affecting grain yield and nitrogen-use efficiency(NUE).However,the underlying regulatory mechanisms on the crosstalk between ethylene-and N-regulated leaf senescence remain a mystery in maize.In this study,ethylene biosynthesis gene ZmACS7 overexpressing(OE-ZmACS7)plants were used to study the role of ethylene regulating leaf senescence in response to N deficiency,and they exhibited the premature leaf senescence accompanied by increased ethylene release,decreased chlorophyll content and F_v/F_m ratio,and accelerated chloroplast degradation.Then,we investigated the dynamics changes of transcriptome reprogramming underlying ethylene-accelerated leaf senescence in response to N deficiency.The differentially expressed genes(DEGs)involved in chlorophyll biosynthesis were significantly down-regulated,while DEGs involved in chlorophyll degradation and autophagy processes were significantly up-regulated,especially in OE-ZmACS7 plants in response to N deficiency.A gene regulatory network(GRN)was predicted during ethylene-accelerated leaf senescence in response to N deficiency.Three transcription factors(TFs)ZmHSF4,Zmb HLH106,and ZmEREB147 were identified as the key regulatory genes,which targeted chlorophyll biosynthesis gene ZmLES22,chlorophyll degradation gene ZmNYC1,and autophagy-related gene ZmATG5,respectively.Furthermore,ethylene signaling key genes might be located upstream of these TFs,generating the signaling cascade networks during ethylene-accelerated leaf senescence in response to N deficiency.Collectively,these findings improve our molecular knowledge of ethylene-accelerated maize leaf senescence in response to N deficiency,which is promising to improve NUE by manipulating the progress of leaf senescence in maize. 展开更多
关键词 ETHYLENE Leaf senescence N deficiency Chlorophyll metabolism AUTOPHAGY Gene regulatory network
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Micro-aluminum powder with bi-or tri-component alloy coating as a promising catalyst:Boosting pyrolysis and combustion of ammonium perchlorate 被引量:1
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作者 Chao Wang ying Liu +6 位作者 Mingze Wu Jia Li ying feng Xianjin Ning Hong Li Ningfei Wang Baolu Shi 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期100-113,共14页
A novel design of micro-aluminum(μAl)powder coated with bi-/tri-component alloy layer,such as:Ni-P and Ni-P-Cu(namely,Al@Ni-P,Al@Ni-P-Cu,respectively),as combustion catalysts,were introduced to release its huge energ... A novel design of micro-aluminum(μAl)powder coated with bi-/tri-component alloy layer,such as:Ni-P and Ni-P-Cu(namely,Al@Ni-P,Al@Ni-P-Cu,respectively),as combustion catalysts,were introduced to release its huge energy inside Al-core and promote rapid pyrolysis of ammonium perchlorate(AP)at a lower temperature in aluminized propellants.The microstructure of Al@Ni-P-Cu demonstrates that a three-layer Ni-P-Cu shell,with the thickness of~100 nm,is uniformly supported byμAl carrier(fuel unit),which has an amorphous surface with a thickness of~2.3 nm(catalytic unit).The peak temperature of AP with the addition of Al@Ni-P-Cu(3.5%)could significantly drop to 316.2℃ at high-temperature thermal decomposition,reduced by 124.3℃,in comparison to that of pure AP with 440.5℃.It illustrated that the introduction of Al@Ni-P-Cu could weaken or even eliminate the obstacle of AP pyrolysis due to its reduction of activation energy with 118.28 kJ/mol.The laser ignition results showed that the ignition delay time of Al@Ni-P-Cu/AP mixture with 78 ms in air is shorter than that of Al@Ni-P/AP(118 ms),decreased by 33.90%.Those astonishing breakthroughs were attributed to the synergistic effects of adequate active sites on amorphous surface and oxidation exothermic reactions(7597.7 J/g)of Al@Ni-P-Cu,resulting in accelerated mass and/or heat transfer rate to catalyze AP pyrolysis and combustion.Moreover,it is believed to provide an alternative Al-based combustion catalyst for propellant designer,to promote the development the propellants toward a higher energy. 展开更多
关键词 Micro-aluminum powder(μAl) Nano-sized alloy coating Combustion catalyst Ammonium perchlorate Pyrolysis behavior Ignition and combustion
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Targeted screening of an anti-inflammatory polypeptide from Rhopilema esculentum Kishinouye cnidoblasts and elucidation of its mechanism in alleviating ulcerative colitis based on an analysis of the gut microbiota and metabolites 被引量:1
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作者 Ziyan Wang Qiuyue Shi +5 位作者 ying feng Jiaojiao Han Chenyang Lu Jun Zhou Zhonghua Wang Xiurong Su 《Food Science and Human Wellness》 SCIE CSCD 2024年第3期1336-1347,共12页
Ulcerative colitis(UC)is a recurrent inflammatory bowel disease that imposes a severe burden on families and society.In recent years,exploiting the potential of marine bioactive peptides for the treatment of diseases ... Ulcerative colitis(UC)is a recurrent inflammatory bowel disease that imposes a severe burden on families and society.In recent years,exploiting the potential of marine bioactive peptides for the treatment of diseases has become a topic of intense research interest.This study revealed the mechanism underlying the protective effect of the dominant polypeptide PKKVV(Pro-Lys-Lys-Val-Val)of Rhopilema esculentum cnidoblasts against DSS-induced UC through a combined analysis of the metagenome and serum metabolome.Specifically,the polypeptide composition of R.esculentum cnidoblasts was determined by matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF/TOF-MS).Molecular docking showed that the dominant peptide PKKVV could bind better with tumor necrosis factor-α(TNF-α)than the original ligand.Subsequent animal experiments suggested that PKKVV could modulate disorganized gut microorganisms in mice with UC;affect serum metabolites through the arachidonic acid,glycerophospholipid and linoleic acid metabolism pathways;and further alleviate UC symptoms.This study provides a reference for the comprehensive development of marine bioactive substances and nonpharmaceutical treatments for UC. 展开更多
关键词 Ulcerative colitis Rhopilema esculentum Kishinouye Cnidoblasts Marine bioactive polypeptides METAGENOME Serum metabolome
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Comprehensive modeling of ignition and combustion of multiscale aluminum particles under various pressure conditions
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作者 Zhenkun HU ying feng +5 位作者 Wei DONG Yong TANG Jia LI Lijuan LIAO Majie ZHAO Baolu SHI 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2024年第11期188-202,共15页
The ignition and combustion of aluminum particles are crucial to achieve optimal energy release in propulsion and power systems within a limited residence time.This study seeks to develop theoretical ignition and comb... The ignition and combustion of aluminum particles are crucial to achieve optimal energy release in propulsion and power systems within a limited residence time.This study seeks to develop theoretical ignition and combustion models for aluminum particles ranging from 10 nm to 1000μm under wide pressure ranges of normal to beyond 10 MPa.Firstly,a parametric analysis illustrates that the convective heat transfer and heterogeneous surface reaction are strongly influenced by pressure,which directly affects the ignition process.Accordingly,the ignition delay time can be correlated with pressure through the p^(b)relationship,with b increasing from-1 to-0.1 as the system transitions from the free molecular regime to the continuum regime.Then,the circuit comparison analysis method was used to interpret an empirical formula capable of predicting the ignition delay time of aluminum particles over a wide range of pressures in N_(2),O_(2),H_(2)O,and CO_(2)atmospheres.Secondly,an analysis of experimental data indicates that the exponents of pressure dependence in the combustion time of large micron-sized particles and nanoparticles are-0.15 and-0.65,respectively.Further,the dominant combustion mechanism of multiscale aluminum particles was quantitatively demonstrated through the Damköhler number(Da)concept.Results have shown that aluminum combustion is mainly controlled by diffusion as Da>10,by chemical kinetics when Da≤0.1,and codetermined by both diffusion and chemical kinetics when 0.1<Da≤10.Finally,an empirical formula was proposed to predict the combustion time of multiscale aluminum particles under high pressure,which showed good agreement with available experimental data. 展开更多
关键词 Multiscale aluminum particles Ignition delay time Combustion mechanism Combustion time PRESSURE
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不同激素对青钱柳外植体和愈伤组织褐化的影响 被引量:10
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作者 冯莹 钱莲文 林庆良 《植物学报》 CAS CSCD 北大核心 2019年第5期634-641,共8页
以青钱柳(Cyclocarya paliurus)叶片为研究材料,采用单因素完全随机试验法比较不同激素(6-BA、GA3和NAA)浓度组合对叶片外植体褐化的影响;在此基础上,分别采用二因素、单因素完全随机试验法比较6-BA+NAA不同浓度组合、不同基本培养基对... 以青钱柳(Cyclocarya paliurus)叶片为研究材料,采用单因素完全随机试验法比较不同激素(6-BA、GA3和NAA)浓度组合对叶片外植体褐化的影响;在此基础上,分别采用二因素、单因素完全随机试验法比较6-BA+NAA不同浓度组合、不同基本培养基对愈伤组织褐化的影响。结果表明,改良MS+1.0 mg·L^–16-BA+1.0 mg·L^–1 GA3+0.3 mg·L^–1 NAA是抑制青钱柳叶片外植体褐化的最佳培养基,其褐化率为0,愈伤组织诱导率100%;改良MS+0.5 mg·L^–16-BA+0.2 mg·L^–1 NAA是抑制愈伤组织褐化的最佳培养基,其褐化率为0,愈伤组织增殖倍数达4.80倍,愈伤组织呈黄绿色或黄色,颗粒状,颗粒小而紧密、质硬且表面干燥。该方法有效解决了青钱柳叶片外植体和愈伤组织褐化问题,为青钱柳组织培养褐化控制提供了一条简单高效的离体培养途径,也为青钱柳叶片离体再生体系的建立奠定基础。 展开更多
关键词 褐化 青钱柳 愈伤组织 诱导 增殖
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双组分层撞击流反应器浓度场混沌分析 被引量:2
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作者 张建伟 许仲荟 +2 位作者 董鑫 冯颖 沙新力 《过程工程学报》 CAS CSCD 北大核心 2022年第6期802-810,共9页
采用平面激光诱导荧光技术测量双组分层式撞击流反应器撞击区浓度分布,利用混沌理论分析不同喷嘴间距、喷嘴直径和射流雷诺数下撞击流反应器浓度场混沌特征参数(关联维、Kolmogorov熵和最大Lyapunov指数)的变化规律。结果表明,撞击流反... 采用平面激光诱导荧光技术测量双组分层式撞击流反应器撞击区浓度分布,利用混沌理论分析不同喷嘴间距、喷嘴直径和射流雷诺数下撞击流反应器浓度场混沌特征参数(关联维、Kolmogorov熵和最大Lyapunov指数)的变化规律。结果表明,撞击流反应器内浓度场混沌特征参数随喷嘴间距的增大呈上下波动的变化趋势,Kolmogorov熵在L=2d时达到最大。浓度场混沌特征参数随喷嘴直径增大呈上下波动的变化趋势,Kolmogorov熵在d=8 mm时整体上最大;射流雷诺数为Re=22000时整体上混沌特征参数最佳。受二次撞击区的影响,撞击面上靠近二次撞击区各点的混沌特征参数有明显提高。 展开更多
关键词 撞击流 浓度场 混沌 关联维 Kolmogorov熵 最大LYAPUNOV指数
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Research Progress of Cognitive Impairment in Post-Traumatic Stress Disorder
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作者 Liumei Luo Yanhai Kang +4 位作者 Fanchang Zeng Yuzhu Lin ying feng Mengmeng Li Feiyan Li 《Health》 2021年第2期157-164,共8页
Post-traumatic stress disorder (PTSD) is a kind of serious mental disorder that occurs after severe traumatic events. It is characterized by severe emotional and memory damage. This paper reviews the relevant research... Post-traumatic stress disorder (PTSD) is a kind of serious mental disorder that occurs after severe traumatic events. It is characterized by severe emotional and memory damage. This paper reviews the relevant research literature on PTSD at home and abroad in recent years, and reviews the mechanism of cognitive impairment in mental trauma to reveal the functional mechanism of cognitive impairment in post-traumatic stress disorder, in order to provide reference for future research. 展开更多
关键词 PTSD Cognitive Function MECHANISM REVIEW
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Study of the Effects of Lower Limb Muscle Strengthening Exercises on Hospitalized Pregnant Women on Bed Rest for Prevention of Miscarriage
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作者 Yu Yang Yanzhen Rao +3 位作者 Ke Sun Qiuying Lin ying feng Xiaoyan Chen 《Open Journal of Nursing》 2020年第12期1241-1250,共10页
<strong>Objective:</strong> Against a background of the two-child policy in China, the objective is to explore the effects of lower limb strengthening exercises on hospitalized pregnant women put on bed re... <strong>Objective:</strong> Against a background of the two-child policy in China, the objective is to explore the effects of lower limb strengthening exercises on hospitalized pregnant women put on bed rest for prevention of miscarriage. <strong>Method:</strong> Sixty cases of pregnant women admitted to the Department of Obstetrics in one of the highest ranking hospitals in Guangzhou, China, during the period from November 2018 to December 2019 for the purpose of preventing miscarriage were selected. They were divided into an experimental group and a control group of 30 cases each. The control group was put under routine care while the intervention group conducted lower limb muscle strengthening exercise on top of the routine care. After the intervention, the conditions of lower limbs, the psychological states and the results of pregnancy for the two groups were compared. <strong>Results: </strong>After the intervention, the scores of the experimental group in anxiety, depression and postpartum depression were lower and leg circumferences were smaller compared to the control group. The difference is statistically significant (<em>P</em> < 0.05). The experimental group had longer gestation than the control group and was able to get out of bed earlier than the control group after delivery, with statistically significant difference (<em>P</em> < 0.05). <strong>Conclusion:</strong> Lower limb muscle strengthening exercises can effectively improve the physiological and psychological states of pregnant women hospitalized for prevention of miscarriage and promote their postpartum recovery. 展开更多
关键词 Prenatal Care EXERCISE Bed Rest Preterm Birth Psychological State
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不同折板絮凝器对薄荷水提液的絮凝效果研究与比较
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作者 冯颖 张庆瑾 +1 位作者 张建伟 张天阳 《过程工程学报》 CAS CSCD 北大核心 2021年第6期695-703,共9页
为了优化折板絮凝器结构及提升折板絮凝器对中药液的絮凝效果,利用FLUENT软件对同波/对波折板絮凝器的内部流场进行了模拟,分析了两种折板絮凝器内的涡旋分布及涡量。以薄荷水提液为研究对象,壳聚糖为絮凝剂,采用不同折板絮凝器对薄荷... 为了优化折板絮凝器结构及提升折板絮凝器对中药液的絮凝效果,利用FLUENT软件对同波/对波折板絮凝器的内部流场进行了模拟,分析了两种折板絮凝器内的涡旋分布及涡量。以薄荷水提液为研究对象,壳聚糖为絮凝剂,采用不同折板絮凝器对薄荷水提液进行絮凝处理,以薄荷水提液澄清层高度、絮体沉降速度、总黄酮保留率、絮凝率、药液吸光度及絮体形态为指标,考察了两种折板絮凝器在不同进液流速下对薄荷水提液的絮凝效果。结果表明,同波折板絮凝器流场内以单侧涡旋为主,对波折板絮凝器内在折板两侧均产生涡旋,相同进液流速下,同波折板絮凝器产生的涡量小于对波折板絮凝器。随进液流速增加,同波/对波折板絮凝器对薄荷水提液的絮凝效果均呈先升高后降低的趋势,同波折板絮凝器最佳进液流速为0.068 m/s,药液总黄酮保留率为91.2%,絮凝率为85.3%;对波折板絮凝器最佳进液流速为0.051 m/s,药液总黄酮保留率为91.8%,絮凝率为85.4%。 展开更多
关键词 折板絮凝器 FLUENT 絮凝 薄荷水提液 壳聚糖
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1,25(OH)_(2)D_(3)调控ERK通路对食管鳞状细胞癌细胞生物学行为的影响 被引量:3
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作者 熊蓉 熊黎 +5 位作者 吴佳林 应凤 岳秋菊 胡欣 刘康 冯刚 《中国肿瘤生物治疗杂志》 CAS CSCD 北大核心 2021年第7期696-701,共6页
目的:探讨1,25-二羟维生素D3[1,25(OH)_(2)D_(3)]对食管鳞状细胞癌(esophageal squamous cell carcinoma,ESCC)细胞增殖、迁移和细胞周期的影响及其相关机制。方法:用不同浓度1,25(OH)_(2)D_(3)处理ESCC细胞TE-11、KYSE30、TE-1和KYSE51... 目的:探讨1,25-二羟维生素D3[1,25(OH)_(2)D_(3)]对食管鳞状细胞癌(esophageal squamous cell carcinoma,ESCC)细胞增殖、迁移和细胞周期的影响及其相关机制。方法:用不同浓度1,25(OH)_(2)D_(3)处理ESCC细胞TE-11、KYSE30、TE-1和KYSE510后,用CCK-8法检测细胞的增殖能力。再用浓度分别是0、0.1、0.15、0.2μmol/L的1,25(OH)_(2)D_(3)处理TE-11和KYSE30细胞,划痕愈合实验、流式细胞术分别检测细胞的迁移能力和细胞周期分布情况,WB法检测细胞中cyclin D1、P27、ERK和p-ERK蛋白的表达水平。结果:1,25(OH)_(2)D_(3)显著抑制TE-11和KYSE30细胞的增殖能力,其抑制程度呈时间依赖性和浓度依赖性。0.1和0.2μmol/L的1,25(OH)_(2)D_(3)处理48 h后,与空白对照组比较,TE-11和KYSE30细胞的迁移能力均显著降低(P<0.05或P<0.01),处于G0/G1期细胞显著增加(P<0.05或P<0.01),细胞中cyclin D1和p-ERK蛋白水平显著下调、P27蛋白水平明显上调(P<0.05或P<0.01)而ERK蛋白的表达无明显变化。结论:1,25(OH)_(2)D_(3)显著抑制ESCC细胞的增殖和迁移能力并阻滞细胞周期进程,其可能通过调控ERK信号通路而发挥作用。 展开更多
关键词 食管鳞状细胞癌 1 25-二羟维生素D_(3) 增殖 迁移 细胞周期 ERK通路
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